1. Field of the Invention
This invention relates to locks and more particularly to the slide lock device.
2. Background of the Invention
Sliding doors have been used in buildings as early as the first century, as evidenced by archeological discoveries in Pompeii, Italy. In modern times sliding doors have evolved into two basic types, either mounted on a floor surface mounted track or suspended from an overhead mounted track. Sliding doors are now commonly used for glass and screen doors. The design of both types of sliding doors contains the same weakness, that of locking the sliding door. Various locks and locking systems have been devised, many have met with limited success. Most locking systems provide for relatively easy access to the sliding door locking mechanism from the interior of a structure and no access on the exterior side of the sliding door. Having a locking system with easy access from the interior side of the sliding door presents the problem of young children unlocking the door and exiting the building.
There have been many in the prior art who have attempted to solve these problems with varying degrees of success. None, however completely satisfies the requirements for a complete solution to the aforestated problem. The following U.S. Patents are attempts of the prior art to solve this problem.
U.S. Pat. No. 889,484 to Parker discloses a pair of sliding sashes. A casing is secured to the upper rail of one of the sashes. A bolt is mounted to slide in the casing having at one end a pair of upwardly extending posts. The posts have outwardly inclined end portions. A headed member is located upon the other sash adapted to be received between the posts and be guided there between by the outwardly inclined portions. A locking screw is adapted to slide the bolt and lock the same in an extended or retracted position.
U.S. Pat. No. 2,855,772 to Hillgren discloses a lock for a sliding door having opposite faces and adapted to enter a slot in a door frame. The lock comprises a casing and a flange at an outside end thereof, a casing element in the casing, a cylinder lock having a key actuated rotatable plug for rotatably secured in the casing element, a separate housing and removable means securing the housing to the casing at a location on the side opposite the flange. The housing has a horizontal slot therein lying in a position diametrical with respect to the rotatable club. A locking bar has a barring end and securing means tiltably securing the bar to the housing in the slot. The bar has an unlocked position flush with the housing and a locking position with the barring end tilted outwardly of the housing. A camway is on a portion of the bar facing the rotatable plug and a cam on an end of the plug facing the bar rotatable to positions on the camway at locations on opposite sides of the securing means whereby to tilt the bar to locked and unlocked positions.
U.S. Pat. No. 2,941,832 to Grossman discloses a lock having a housing and a stop member mounted in the housing for movement between a retracted position within the housing and a position in which the member extends from the housing. Detent means are mounted on the stop member and engageable with a housing, when the stop member extends from the housing, to prevent shifting of the stop member to the retracted position. The detent means has a portion engageable with the housing, when the stop member extends from the housing, to retain the detent means on the stop member. A generally U-shaped spring are in the housing having rear and front arms. The rear arm engage the housing. The front arm engages the stop member to yieldably hold the stop member in its retracted and extended positions.
U.S. Pat. No. 3,944,266 to Weaver discloses a latch structure incorporating a housing and a bolt plate movable therein attachable to an edge of a sliding door adjacent a corner thereof where the bolt plate may move into registry with openings formed in a flanged track in which the sliding door moves. A fastener secures the housing to the edge of the door and a thumb screw engages the bolt plate through a slot in the housing to enable the bolt plate to be moved relative to the housing and secured in fixed position relative thereto.
U.S. Pat. No. 4,436,329 to Metzger discloses a novel locking mechanism for a sliding window or door of the type having an outer surrounding rectangular frame mounted to a wall, and an inner transparent pane mounted to a second rectangular frame slidably mounted within the outer frame. The locking mechanism is incorporated within one side of the inner frame and comprises a slide, a latch adapted to move and lock the slide, a deadbolt attached to the slide and adapted to extend into the outer frame to lock the two frames together, and a latch accessed through a latch port defined in the side of the inner frame. The latch port comprises a wider locking segment and a narrower adjacent unlocking segment, and the latch comprises a post attached to the slide and a button slidably mounted on the post and sized to extend through the wider locking segment of the latch port. A coil spring surrounding the post forces the button into the wider locking segment when the deadbolt is in the lock position, thus maintaining the latch and slide in a vibration-resistant configuration until the button is depressed through the wider locking segment and transported along the unlocking segment of the port.
U.S. Pat. No. 4,514,996 to Sjogren discloses a sliding door lock in which a bolt is longitudinally slidable by manual movement of a handle to which the bolt is connected so that the bolt is axially rotatable to prevent the cutting of the bolt when locked. The handle slides linearly along a base plate to move the bolt between opened and closed positions. A bullet latch in the handle engages detents on the base plate to hold the handle and bolt in the open and closed positions. A key-operated barrel lock has a barrel groove through which the bolt passes when the lock is in the unlocked position, and the bolt has a circumferential constriction which receives the barrel lock barrel when the barrel lock is rotated to its locked position, thereby preventing movement of the handle and bolt to the open position.
U.S. Pat. No. 4,530,531 to Mantini discloses a device for securing sliding closures such as a door or window slidable in an appropriate track in a frame. First and second latch sections are provided, one securable to the closure and the other securable to the frame by appropriate fasteners. The latch sections have complementary walls defining a substantially closed compartment which conceals the fasteners when the closure is in a closed position relative to the frame. The latch sections prevent the closure from being lifted out of the track.
U.S. Pat. No. 5,152,561 to Engebretson discloses a door handle and latch assembly for a sliding door comprising a main body having a finger gripping recess on one side facing outwardly to permit opening and closing of a sliding door and a latch member having an L-shaped bracket overlying a vertical edge of a door. The main body of the latch is located in a recess formed in the main body on the side opposite the side of the finger gripping recess. The recess is bounded also by a surface on the sliding door to form a channel in which the latch member can move up or down to lock and unlock the sliding door.
U.S. Pat. No. 5,228,733 to Winters discloses a safe and taper resistant safety lock system for the top of sliding glass doors and consists of a metal bracket fastened to the top edge of the door, positioned on the door with a screw which is normally found in each door, and then permanently fastened to the door with a second screw. A top, horizontal section, is formed by bending a first end of a metal plate, and extends over the top of the sliding door. The safety lock system is adjusted to reduce the gap between the top of the door and the top of the upper track to prevent lifting of the door out of the bottom track.
U.S. Pat. No. 5,284,371 to Richardson, et al. discloses a sliding door lock having a latch plate, which slidably engages a channel in one leg of a corner piece. The corner piece is mounted in a door frame. A stud is attached to the slider plate so that a person may grasp the stud and slide the plate up and down. The stud has internal threads. A small screw is threaded into the internal threads of the stud. The sliding door lock is used by grasping the stud, which extends through an elongated slot in the door frame, and using the stud to move the latch plate upward so that it extends past the top of the door frame. The small screw is then used to hold the latch plate in an upward position. A tool is used to thread the small screw past the end of the stud so that the end of the small screw is in frictional contact with the corner piece, thus holding the latch plate in the upward position. When the latch plate is locked in the upward position, the door cannot be slid open because the upper end of the plate will come into contact with a block positioned above the door frame and mounted on a supporting structure surrounding the door frame. The latch plate may also be used in conjunction with other blocks for the purpose of holding the sliding door open.
U.S. Pat. No. 5,676,408 to Davidian discloses a pocket door latch assembly has a housing with a latch arm pivotally mounted therewithin. The latch arm has a latch nose at one end and an inverted generally V-shaped slot adjacent its other end, and the arm is pivotable between a first position wherein it is entirely within the housing and a second position wherein the latch nose extends outwardly of the housing. An actuator has a portion slidable within the slot between a first position adjacent the one end of the arm and a second position spaced from the one end to pivot the latch arm between its first and second positions. The actuating means is manipulable outwardly of the housing to slide the slidable portion of the actuating means within the slot between its first and second positions, thereby pivoting the latch arm between its positions.
U.S. Pat. No. 6,000,735 to Jourdenais discloses a magnetically actuated safety lock device providing automatic locking capability to doors such as sliding glass patio doors and prevents unsupervised opening of the door by young children, thereby barring their access to dangerous environments. When the sliding door is closed, it is automatically locked. The lock device is installed in a position high upon the sliding door to prevent actuation by young children and requires no permanent modification to the door on which it is installed. The lock device consists of a locking assembly and a magnetic key. The locking assembly includes a magnetized latch assembly and a mounting bracket. The latch is held in the locked position by gravity and is only rotated into the unlocked position through the application of hand pressure or the repulsive force of the magnetic key. The doors can be unlocked from both inside and outside the door. Upon removal of either the magnetic force or hand pressure, the latch rotates back into the locked position. The latch is designed with an angled surface on one side such that as the user closes the door behind him, the door can close normally. This angled surface in the latch allows the door to slide along its track in the closing direction and, as the door edge touches the latch at the angled surface, the latch is rotated by the door into the unlocked position. Once the frame of the door slides completely past the latch, the latch rotates back into the locked position.
U.S. Pat. No. 6,443,504 to Donald discloses a sliding door latch with a finger pull mechanism that fits within a standardized aperture normally utilized for a hinged door latch. Provided is a latch assembly having an extendable latching hook for mounting in a sliding door and latching with a strike plate mounted in a door frame and a finger pull mechanism for accessing the sliding door from within a surrounding framework. Included are a housing assembly for fitting within the sliding door, an exposed edge plate mounted to the edge of the sliding door beside the housing assembly, a latching hook for engaging with the strike plate and extendable through the exposed edge plate, and a finger pull mechanism mounted in the edge plate.
U.S. Pat. No. 6,702,340 to Donald discloses a sliding door latch with a finger pull mechanism that fits within a standardized aperture normally utilized for a hinged door latch. Provided is a latch assembly having an extendable latching hook for mounting in a sliding door and latching with a strike plate mounted in a door frame and a finger pull mechanism for accessing the sliding door from within a surrounding framework. Included are a housing assembly for fitting within the sliding door, an exposed edge plate mounted to the edge of the sliding door beside the housing assembly, a latching hook for engaging with the strike plate and extendable through the exposed edge plate, and a finger pull mechanism mounted in the edge plate.
U.S. Pat. No. 7,246,829 to Balsbaugh, et al. discloses an improved sliding door latch comprising a latch plate attached to the leading edge of the door and projecting outwardly on either side of the door to enable a person to grasp the latch plate to slide the door open or closed, and a latch arm pivotally secured to the doorjamb and movable between a first unlocked position which permits the door to be opened or closed and a latched position engaging the latch plate and preventing movement of the door.
Although the aforementioned prior art have contributed to the development of the art of sliding door locks, none of these prior art patents have solved the needs of this art.
Therefore, it is an object of the present invention to provide an improved apparatus for locking a sliding door.
Another object of this invention is to provide an improved apparatus for preventing children from opening a locked sliding door.
Another object of this invention is to provide an improved apparatus that is simple for the adult operator to use.
Another object of this invention is to provide an improved apparatus that is easy to cost effectively produce.
Another object of this invention is to provide an improved apparatus that is easy to install on new or existing sliding door systems.
The foregoing has outlined some of the more pertinent objects of the present invention. These objects should be construed as being merely illustrative of some of the more prominent features and applications of the invention. Many other beneficial results can be obtained by modifying the invention within the scope of the invention. Accordingly other objects in a full understanding of the invention may be had by referring to the summary of the invention, the detailed description describing the preferred embodiment in addition to the scope of the invention defined by the claims taken in conjunction with the accompanying drawings.